Trait derive_visitor::DriveMut
source · [−]pub trait DriveMut: Any {
fn drive_mut<V: VisitorMut>(&mut self, visitor: &mut V);
}Expand description
Drive a VisitorMut over this datastructure.
This is equivalent to Drive, but gives the possibility to mutate the datastructure as it is visited.
Example
use derive_visitor::{DriveMut, Event, visitor_fn_mut};
#[derive(DriveMut, Default)]
struct Node{ children: Vec<Node> }
let mut node = Node{children: vec![Node::default(), Node::default()]};
node.drive_mut(&mut visitor_fn_mut(|n: &mut Node, event|
// Mutate the element on exit so that we are not driven to the newly created elements
if let Event::Exit = event {
n.children.resize_with(3, Default::default);
}
));
// We have driven over all the initial nodes...
assert_eq!(node.children.len(), 3);
assert_eq!(node.children[0].children.len(), 3);
assert_eq!(node.children[1].children.len(), 3);
// ... but not over the newly created ones
assert_eq!(node.children[2].children.len(), 0);Required Methods
source